The large dark oval in the left half is a pond.

In the center of the pond is a person doing the backstroke.
A bit farther to the left, another person is swimming.
Farther to the left, some people are standing on the shore,
and one is about to dive in.

Looking towards the center, there is a person,
arms raised in the air, jumping into the pond
from the rocks in the right half of the picture
that overlook the pond. Some people are resting
on the rocks after having a picnic.

Really, it's backlit ice with polarizing filters in front of and behind the ice.